Gears question
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JK Freak
Joined: May 2011
Posts: 562
Likes: 0
From: Winter Haven, FL
Originally Posted by nthinuf
Being under-geared and constantly dropping in and out of OD is what will kill the trans. (and mpg's). Being geared correctly for your tires will keep you in OD, keep the trans temps down, (prolonging the life of the trans), and should improve the mpg's.
Which brings up the debate of lower rpm's vs higher rpm's.
-low rpm's give better mpg's (4.88's)
-higher rpm's keeps you in OD longer before downshifts (5.13/5.38)
Decide what rpm's 'you' need to run to be able to hold freeway speeds without downshifts. Sea level with long flat freeways? Lots of hills, few flat stretches? At altitude with mountain roads? Lift and tires? Armor and winch and carrier? 2door or 4door? (for me, whether I am up in Colorado or down in Texas, 5.38's perform better than 5.13's).
Whichever ratio you decide on, you should also look into a trans cooler. They are cheap and pretty easy to install.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Here is a write-up for a popular B&M cooler. There are also some posts/write-ups about swapping the rubber lines for metal lines, which may be something to look into if/when you do this.
https://www.jk-forum.com/forums/show...mission-Cooler
That is the one I got from Summit 3 years ago, not sure if there is anything better out there to look into these days. At least it gives you a proven cooler to compare against.
https://www.jk-forum.com/forums/show...mission-Cooler
That is the one I got from Summit 3 years ago, not sure if there is anything better out there to look into these days. At least it gives you a proven cooler to compare against.